Sports Vehicle

ABSTRACT

A sports vehicle which includes a substantially horizontal platform [( 1 )] capable of supporting the user and having attached to its underside two or more rotatable disks [( 2 )] arranged to rotate about substantially vertical axes [( 3 )], the underside of each rotatable disk being substantially convex in form. The platform is resilient and can adopt a convex or concave shape, so as to steer the vehicle. The user places his feet on the platform and steers the vehicle by tilting the platform using his body weight. The vehicle enables its user to travel over grassland and similar terrain in a manner similar to skateboarding and snowboarding.

TECHNICAL FIELD

[0001] This invention relates to a sports vehicle that enables a personto travel downhill over terrain whose surface characteristics wouldrender the use of a skateboard or snowboard impracticable, and inparticular to a sports vehicle which may be ridden by a person standingon a platform on the vehicle.

BACKGROUND OF THE INVENTION

[0002] Devices such as the skateboard and snowboard are well known. Theskateboard enables its user to travel over surfaces such as tarmac andconcrete, which are relatively smooth and firm. The snowboard enablesits user to travel over snow-covered surfaces, which offer a lowcoefficient of friction. Neither of these devices is suitable fortravelling over grassland or any other terrain that lacks the smoothnessand firmness required by the skateboard and the low coefficient offriction required by the snowboard.

SUMMARY OF THE INVENTION

[0003] The object of this invention is to provide a device that enablesits user to indulge in pursuits similar to skateboarding andsnowboarding over terrain such as grassland.

[0004] According to a first aspect of the present invention, there isprovided a vehicle for travelling over grassland and similar terrain,said vehicle comprising a generally horizontal platform having attachedto its underside one or more rotatable disks each having a lower surfaceadapted to contact the ground, each of said one or more rotatable disksarranged to rotate about a generally vertical axis, the underside ofeach of said one or more rotatable disks being substantially convex inform.

[0005] Preferably, said vehicle has two or more rotatable disks arrangedalong a longitudinal axis of said platform.

[0006] Preferably, said platform is resiliently pliable. Preferably,said platform comprises a first area on its upper side towards the frontof said platform adapted to receive one foot of the user, and a secondarea on its upper side towards the rear of said platform adapted toreceive the other foot of the user, said platform comprising a centralportion between said first and second areas adapted to flex resilientlyabout a lateral axis in the plane of said platform. Preferably, saidfirst and second areas are provided with boot or shoe retention means.The platform may further comprise a hinge mechanism extending laterallyacross said platform to aid pliability. The first area of the platformmay be provided with a first rotatably mounted foot support member,while the second area of the platform may be provided with a secondrotatably mounted foot support member. Preferably each foot supportmember is rotatably mounted such that its axis of rotation issubstantially coincident with the axis of rotation of a rotatable disk.Preferably said first and second foot support members are each providedwith boot or shoe retention means.

[0007] Preferably, said central portion comprises a portion of saidplatform having a reduced cross-sectional area. Preferably, said centralportion comprises a waist portion of the platform having a reducedwidth.

[0008] In one embodiment the platform may have a generally concave shapein a longitudinal direction in its unstressed state, such that thecentral portion of the platform is lower than the ends of the platform.In another embodiment the platform may have a generally convex shape ina longitudinal direction in its unstressed state, such that the centralportion of the platform is higher than the ends of the platform.

[0009] Preferably, each of said one or more rotatable disks is supportedon a spindle attached to the underside of said platform. Preferably,said vehicle further comprises additional support means adapted toprovide additional support for each of said one or more rotatable disksin addition to said spindle. Preferably, said additional support meansis either a plurality of idler wheels or rollers. Alternatively, each ofsaid one or more rotatable disks is supported solely by either aplurality of idler wheels, a plurality of rollers, or a plurality ofballs.

[0010] Preferably, each of said one or more rotatable disks is solid.

[0011] Alternatively, each of said one or more rotatable disks ishollow, said upper surface of each of said one or more rotatable disksbeing substantially concave in form. Preferably, said platform is shapedso as to follow the form of said concave upper surface of each of saidone or more hollow rotatable disks.

[0012] Preferably, the lower surface of each of said one or morerotatable disks is substantially in the form of part of the surface of asphere. Alternatively, the lower surface of each of said one or morerotatable disks may be substantially in the form of part of the surfaceof an ellipsoid, a truncated cone, or a truncated toroid.

[0013] Preferably, said vehicle further comprises means for theattachment of a sail, to permit the user to traverse substantially levelterrain.

[0014] Preferably, the platform and rotatable disks are made ofcomposite plastics materials, and the other parts that support therotatable disks are made of metal, but the platform may instead be madeof natural materials, such as wood, and the rotatable disks may be madeof metal.

[0015] According to a second aspect of the present invention there isprovided a vehicle for travelling over grassland and similar terrain,said vehicle comprising a substantially horizontal platform havingattached to its underside three or more rotatable disks arrangedlongitudinally, at least one of said rotatable disks having a firstinclined axis, and at least one rotatable disk having a second inclinedaxis inclined in the opposite sense to said first inclined axis.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] A preferred embodiment of the invention will now be describedwith reference to the accompanying drawings in which:

[0017]FIGS. 1a and 1 b show a side elevation and plan view respectivelyof a vehicle according to the invention, with the mounting spindle shownschematically;

[0018]FIGS. 2a and 2 b show an end elevation and plan view respectivelyof the vehicle of FIG. 1 with the platform parallel to the ground;

[0019]FIGS. 3a and 3 b show an end elevation and plan view respectivelyof the vehicle of FIG. 1 with the platform tilted to one side;

[0020]FIGS. 4a and 4 b show a side elevation and plan view respectivelyof the vehicle of FIG. 1 when positioned on a sloping surface;

[0021]FIGS. 5a and 5 b show a side elevation and plan view respectivelyof another vehicle according to the invention having two rotatable diskswith the platform flat, the mounting spindles being shown schematically;

[0022]FIGS. 6a and 6 b show a side elevation and plan view respectivelyof the vehicle of FIG. 5 with the platform curved upwards towards itsends;

[0023]FIGS. 7a and 7 b show a side elevation and plan view respectivelyof the vehicle of FIG. 5 with the platform curved downwards towards itsends;

[0024]FIG. 8a shows a longitudinal section through a vehicle accordingto the invention showing the rotatable disk mounting arrangement with acentral spindle;

[0025]FIG. 8b is an enlarged view of part of the longitudinal section ofFIG. 8a;

[0026]FIG. 9 shows a transverse section through a solid rotatable diskof the vehicle of FIG. 8a;

[0027]FIG. 10 shows a transverse section through a hollow rotatabledisk;

[0028]FIG. 11 shows a transverse section through a rotatable diskmounting arrangement with no central spindle of another vehicleaccording to the invention;

[0029]FIG. 12 shows a transverse section through another platformaccording to the invention in which the platform follows the form of therotatable disks;

[0030]FIGS. 13a and 13 b show a side elevation and an end elevationrespectively of a vehicle according to a further embodiment of theinvention;

[0031]FIG. 14 shows a plan view of a vehicle according to a furtherembodiment of the invention having rotatable foot supports; and

[0032]FIG. 15 shows a plan view of the vehicle of FIG. 15 with the footsupports in a rotated position.

DETAILED DESCRIPTION OF THE INVENTION

[0033] In the embodiments illustrated in FIGS. 1 to 4, the vehicleaccording to the invention comprises a platform 1 capable of supportingthe user and having on its underside one or more rotatable disks 2. Eachrotatable disk 2 rotates about a spindle 3, which is attached at one endto the underside of the platform with its axis perpendicular to theunderside of the platform. The user stands on the platform, with hisfeet in approximately the position 4 shown in FIG. 1, and he may adopt acrouching stance to enable him to grip handgrips 5 located at each endof the platform.

[0034] When the platform 1 is parallel to the ground, as shown in FIG.2, the point of contact 20 with the ground 30 of each rotatable disk 2(as seen in plan view) is coincident with the [centre] center of therotatable disk 2, and any force applied in the plane of the platform 1will not result in a turning moment being applied to the rotatable disks2. However, when the platform 1 is tilted to one side, as shown in FIG.3, the point of contact 22 of each disk 2 with the ground 30 is notcoincident with the [centre] center 24 of the rotatable disk 2, and aforce applied to the platform 1 will normally cause a turning moment tobe applied to the rotatable disks 2.

[0035] As shown in FIG. 4, when the platform 1 is resting on a slopingsurface 32 of sufficient gradient, and is tilted in a direction otherthan the direction of maximum gradient, the turning moment induced inthe rotatable disks 2 is sufficient to overcome the friction that existsat the point of contact 22 with the ground 32, and the device travels ina downhill direction.

[0036]FIG. 5 shows an embodiment of the vehicle of the invention havingtwo rotatable disks 2 and a pliable platform 1 with handgrips 5 at eachend. When the platform 1 is flat, the imaginary lines 40 joining the[centre] center 24 of each rotatable disk 2 to its point of contact 22with the ground (as seen in plan view) are perpendicular to thelongitudinal axis of the platform, and the vehicle travels in thedirection of the longitudinal axis, indicated by the arrow 42. However,if the ends 44 of the platform are pulled upwards by the user pulling onthe handgrips 5, causing the platform 1 to assume a curvature of thetype shown in FIG. 6, that is a concave curvature of the upper face ofthe platform 1, the imaginary lines 46 joining the [centre] center 24 ofeach rotatable disk 2 to its point of contact 22 a with the ground areno longer perpendicular to the longitudinal axis and the vehicle steerstowards the side 45 to which it has been tilted, in the direction of thearrow 48. Conversely, if the ends 44 of the platform 1 are pusheddownwards by the user, causing the platform to assume a curvature of thetype shown in FIG. 7, that is a convex curvature of the upper face ofthe platform 1, the device steers towards the opposite side, in thedirection of arrow 52. The imaginary lines 50 joining the [centre]center 24 of each rotatable disk 2 to its point of contact 22 b with theground are not perpendicular to the longitudinal axis and the vehiclesteers away from the side to which it has been tilted.

[0037]FIGS. 8a and 8 b show a detailed embodiment of a vehicle accordingto the invention. In this embodiment, handgrips 5 a are provided in theform of a longitudinal extension of the platform 1 at each end of theplatform beyond the outer edge of the adjacent rotatable disk 2. A metalspindle 3 is attached by bolts 60 or other means to the underside of theplatform 1. Rolling element bearings 6 are fitted between the spindle 3and the rotatable disk 2 to reduce the friction and wear arising fromrotation of the rotatable disk on the spindle, and the assembly is madesecure by a nut 7 secured to the threaded end 62 of the spindle 3, sothat the two bearings 6 are held between the nut 7 and a shoulder 64provided at the upper end of the spindle 3.

[0038] The underside of each of the rotatable disks 2 may take a varietyof forms, including a segment of a sphere, a segment of an ellipsoid, atruncated cone, a truncated toroid or a combination of these forms. Thechoice of form is dictated by the contact area required to prevent therotatable disk sinking into the ground; the nature of the undulationsinherent in the terrain over which the device is to be used; and therequirement that the device should not be unduly difficult to balance.

[0039] The rotatable disks 2 may be of solid construction, as shown inFIG. 9, or hollow construction, as shown in FIG. 10. The material may bea [mouldable] moldable plastic or resin, metal, alloy, composite or anymaterial which can be formed and has the requisite strength andstiffness. Hollow rotatable disks have an outer shell 70 and may haveinternal ribs 76 (shown in FIG. 13a) to increase their stiffness. Wherehollow construction is used, as shown in FIG. 10, one or more idlerwheels 8 may be employed to provide additional support to the rotatabledisks 2, as shown in FIG. 10. Each idler wheel is rotatably mounted on abracket (not shown) which is fixed to the underside of the platform 1.The wheel 8 is oriented so that its axis or rotation 72 is parallel tothe contact surface 74 on the disk 2. The provision of idler wheels 8serves to reduce the bending moment which must be withstood by thespindle 3 and its bolted connection to the platform 1. It is to beunderstood that roller or balls may be used to support the edges of thedisks 2 in the same way as the idler wheels 8 described above.

[0040]FIG. 11 shows an alternative form of rotational support by meansof which a disk 2 may be rotatably mounted on the platform 1. Aplurality of balls 9 are mounted circumferentially in a ball supportchannel formed by an outer flange 80 attached to the disk 2 and an innerflange 82 mounted securely to the underside of the platform 1. It is tobe understood that other forms of roller or ball bearing which extendaround the circumference of the rotatable disk 2 may be used.

[0041] Where hollow rotatable disks 2 are used, the platform 1 may beformed in such a way that it follows the form of the upper surface 90 ofthe rotatable disks 2, as shown in FIG. 12. The user's feet are placedin the concave section of the platform 1. This configuration enables theuser to remain closer to the ground and to stand on a surface that isapproximately parallel to the ground, since if the user applies weightat a point 92 to one side of the longitudinal axis of the platform 1,then the vehicle 1 will tilt about the longitudinal axis so that thepoint 94 on the disk 2 comes into contact with the ground 30 and theadjacent part of the platform at point 92 is substantially parallel tothe ground 30. In addition, this concave section could be adapted toprovide a flat, horizontal surface for the user's feet when the platformis tilted to the appropriate angle, if the upper surface is profiled tothe shape shown by the dotted line 96.

[0042] A further embodiment of the invention is shown in FIG. 13 whichhas three rotatable disks 2 mounted on the underside of the platform 1.The two rotatable disks 2 a at the ends of the platform 1 are tilted bya particular tilt angle about the longitudinal axis of the platform 1 inone direction, whilst the central rotatable disk 2 b is angled by thesame or similar tilt angle in the opposite direction. With thisarrangement, the platform 1 remains horizontal, but the vehicle canstill be steered by deflection of the platform 1 as with the otherembodiments.

[0043]FIGS. 14 and 15 illustrate an embodiment in which the top of theplatform 1 is provided with rotatable foot support members 100 which areconnected by a rotatable hinge 102 to a point on the upper surface ofthe platform 1 corresponding to the [centre] center of rotation of thedisk 2. The foot support members 100 in the illustrated embodiment arein the form of rigid plates, which may have rollers, bearings orlow-friction coatings (not shown) on their underside so that they canrotate freely with respect to the platform 1. The same spindle 3 used tomount the rotatable disk 2 can also be used to mount the hinge 102. Inthis way the foot support members 100 can rotate about axes coincidentwith the axes of the rotatable disks 2. The user places his feet on thefoot support members 100 and applies his weight through his heels in thenormal manner to tilt the platform to one side. If he then moves hisheels closer together and thereby rotates the foot support members 100to the position 100 a in FIG. 15, then the platform will assume a“concave up” position, as shown in FIG. 6, causing the vehicle to steerto one side. If he moves his heels further apart and thereby rotates thefoot support members 100 to the position 100 b in FIG. 15, then theplatform will assume a “concave down” position, as shown in FIG. 7,causing the vehicle to steer to the other side. The foot support membersmay be of any suitable shape and may be fitted with boot or shoeretention devices, such as a simple toe strap 104 or any device of thesort known in the art of snowboarding, skiing and roller skating.

[0044] The device could also be provided with means to which a sail andmast may be attached, if the user was to traverse substantially levelterrain. The attachment of such a sail would therefore enable the userto cross terrain with the minimum of effort being required.

[0045] Pliability of the platform 1 may be achieved by constructing itentirely of flexible materials, or by using a combination of rigidmaterials in the vicinity of the user's feet and flexible materials forthe middle portion. A region of reduced cross-sectional area may also beincorporated in the platform to facilitate deflection, or a mechanicalhinge (not shown) may be employed, which extends across the width of theplatform. The hinge may have some form of damping arrangement, toprevent the platform from being too flexible.

[0046] The illustrated embodiments show the platform 1 to have agenerally flat shape in the unstressed state. However it is to beunderstood that the platform may, in its unstressed condition, have aconcave or convex upper surface, of the form illustrated in FIGS. 6a or7 a respectively. Having such a shape will give the vehicle a naturaltendency to steer to one side or the other in the absence of a specificdeflection of the platform by the user. In such circumstances a user canadopt a zigzag course by standing on one side of the platform 1 whileproceeding on a first leg of the zigzag course, then at the turningpoint rotating the board through 180° about a vertical axis and standingon what is effectively the other side of the platform 1 while proceedingon the second leg of the zigzag course.

[0047] These and other modifications and variations are possible withoutdeparting from the scope of the invention.

1. A vehicle for travelling over grassland and similar terrain, said vehicle comprising a generally horizontal platform having attached to its underside two or more rotatable disks each having a lower surface adapted to contact the ground, each of said two or more rotatable disks arranged to rotate about a generally vertical axis, the underside of each of said [one] two or more rotatable disks being substantially convex in form.
 2. [A] The vehicle according to claim 1, wherein said two or more rotatable disks are arranged along a longitudinal axis of said platform.
 3. [A] The vehicle according to claim 1, wherein said vehicle has two rotatable disks arranged along a longitudinal axis of said platform.
 4. [A] The vehicle according to [any preceding] claim 1 wherein said platform is resiliently pliable.
 5. [A] The vehicle according to [any preceding] claim 1, wherein said platform comprises a first area on its upper side towards the front of said platform adapted to receive one foot of the user, and a second area on its upper side towards the rear of said platform adapted to receive the other foot of the user, said platform comprising a central portion between said first and second areas adapted to flex resiliently about a lateral axis in the plane of said platform.
 6. [A] The vehicle according to claim 5, wherein the first area of the platform is provided with a first rotatably mounted foot support member, and the second area of the platform is provided with a second rotatably mounted foot support member.
 7. [A] The vehicle according to claim 6, wherein each foot support member is rotatably mounted such that its axis of rotation is substantially coincident with the axis of rotation of a rotatable disk.
 8. [A] The vehicle according to claim 6 [or 7], wherein said first and second foot support members are each provided with boot or shoe retention means.
 9. [A] The vehicle according to [any preceding] claim 1, wherein said central portion comprises a portion of said platform having a reduced cross-sectional area.
 10. [A] The vehicle according to [any preceding] claim 1, wherein the platform has a generally concave shape in a longitudinal direction in its unstressed state, such that the central portion of the platform is lower than the ends of the platform.
 11. [A] The vehicle according to [any one of claims 1 to 9] claim 1, wherein the platform has a generally convex shape in a longitudinal direction in its unstressed state, such that the central portion of the platform is higher than the ends of the platform.
 12. [A] The vehicle according to [any preceding] claim 1, wherein each of said [one] two or more rotatable disks is supported on a spindle attached to the underside of said platform.
 13. [A] The vehicle according to claim 12, wherein said vehicle further comprises additional support means adapted to provide additional support for each of said [one] two or more rotatable disks in addition to said spindle.
 14. [A] The vehicle [as claimed in] according to claim 13, wherein said additional support means is a plurality of idler wheels.
 15. [A] The vehicle [as claimed in] according to claim 13, wherein said additional support means is a plurality of rollers.
 16. [A] The vehicle [as claimed in any of claims 1 to 12] according to claim 1, wherein each of said [one] two or more rotatable disks is supported by a support means selected from the group of support means comprising a plurality of idler wheels, a plurality of rollers, and a plurality of balls.
 17. [A] The vehicle according to [any preceding] claim 1, wherein each of said [one] two or more rotatable disks is solid.
 18. [A] The vehicle according to [any one of claims 1 to 16] claim 1, wherein each of said [one] two or more rotatable disks is hollow, said upper surface of each of said [one] two or more rotatable disks being substantially concave in form.
 19. [A] The vehicle according to claim 18, wherein said platform is shaped so as to follow the form of said concave upper surface of each of said [one] two or more hollow rotatable disks.
 20. [A] The vehicle according to [any preceding] claim 1, wherein the lower surface of each of said [one] two or more rotatable disks is substantially in the form of part of the surface of a sphere, an ellipsoid, a truncated cone, or a truncated toroid.
 21. [A] The vehicle according to claim 2, the axis of rotation of at least one of said rotatable disks being inclined in a first rotational sense about the longitudinal axis of the platform, and the axis of rotation of at least one other rotatable disk being inclined in an opposite rotational sense about the longitudinal axis of the platform.
 22. [A] The vehicle according to claim 21, wherein the platform has attached to its underside three or more rotatable disks arranged along the longitudinal axis of said platform. 